Drafting device



L. C. HAHN.

DHAFTING DEVICE.

APPLICATION man MAR. 22, 1919.

Patented Jun. 27, 1920.

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LOUIS CHRISTOPHER HAHN, OF CINCINNATI, OHIO.

DRAFTING DEVICE.

Specification of Letters Patent.

Patented Jan. 27, 1920.

Application filed March 22, 1919. Serial N0. 284,352.

To all whom it may concern:

Be it known that I, Louis C. HAHN, a citizen of the United States, and a resident of Cincinnati, in the county of Hamilton and State of Ohio, have invented certain new and useful Improvements in Drafting Devices, of which the following is a specification.

The present invention relates to a drawing and measuring instrument, and has for its primary object to provide a device of this character in which a number of instruments are combined in one, and in which the different instruments may be used independently or in combination with each other, according to the result sought to be accomplished.

A further object of the invention is to provide an instrument as above outlined, which may be stamped from a single piece of metal and in which all of the instruments are integral with each other and permanently fixed on the same plane.

Vith these and other objects in view, the invention will be more readily understood upon reference to the accompanying drawing, in which- Figure 1 is a plan View of the instrument, and

Fig. 2 is a side elevation.

Referring to the drawings in detail, A represents the instrument, which primarily comprises a T-square 1 having an elongated extension 2 divided up into a plurality of integral rules 3, having graduations along their edges, as at A, some of the graduations, such as at 5, being of different de nominations, as for example, 16ths, inds and 6Aths, of an inch. The advantage of the plurality of rules resides in providing means for drawing parallel lines of equal distances apart. In the place between the edges of one of the rules, I provide an angle 6 and a pair of triangles 7 and 8, all of which being cut out of the metal blank. The end of the alongated extension is provided with a scroll 9 and a star 10, sur rounded by a graduated circle 11. 12 represents cut-out portions, which may be used in erasing. On the transverse head of the T-square I also propose to provide a pencil Sharpener 13 and a pointer 14.

On one end of the -square is a protractor segment 15, and a series of perforations 16 are provided along a medial line on the elongated extension. These perforations are composed of practically two series, for instance those indicated as 16 and a second series 17, which are closer together than the ones 16, the former coinciding with the axis of the protractor represented by the perforation 18. The perforations are employed in drawing circles or curved lines; in doing so the axis of the protractor is used as a pivot point and a pencil point in inserted in one of the perforations in either one of the series 16 or 17, according to the desired radius of the circle or curved line to be produced. The combination of the protractor segment and these perforations will enable the instrument to be used to produce curved linesor circles with any desired radius, the same to be accurately reckoned bv the graduations on the protractor. The perforations are, of course, spaced in a manner to make this possible.

Claims:

1. A drawing instrument, comprising an elongated plate having at one end a protractor segment, alined series of perforations extending along the plate at measured distances, one of said series coinciding with the axis of said protractor segment.

2. A drawing instrument, comprising an elongated plate having at one end a protractor segment, a lined series of perforations extending along the plate at measured distances, one of said series coinciding with the axis of said protractor segment and spaced closer together than the other of said series.

LOUIS CHRISTOPHER HAHN. 

